January 2018, I have bought a 15W Acan A12 chinese made laser engraver. The kit arrived properly packed. Assembly took about 20 minutes, a total of 8 screws attached the loose parts and 5 kables needed to be connected. I run the Windows Acan software on my MacBook Air on Parallels. One driver needed to be installed as well. All in all - pretty easy. After reading the software manual I used the image which was used for lasering before on other machines and did my first test on cardbord. The second test was made on a copper plate. The result is amazing and I thing after some testing my project to make a enamel style pocket watch face completly myself at home will be a success.
Very important, ALWAYS use the safety glasses, have a well ventilated room and soom exhaust ventilation!
Testing the settings, this is a bit try and error as every material needs different settings. There is no other way as to do some test series. The different settings you can alter are plenty. One setting which should also be altered is the focal length, the distance the laser diode is from the object. The machine is set to a focal length of 18 mm but the best results sofar are with 18,5 mm.
One weak spot is the mounting table, it is to wobbly. I solved the problem for the time being with an iron block.